Polybiphenyl sulfone polymers belong to the polyarylene ether group, and are therefore engineering thermoplastics. Polybiphenyl sulfone polymers have not only high heat resistance but also superior notched impact resistance and excellent fire performance.
The production of polybiphenyl sulfone polymers is disclosed by way of example in DE 1957091 and EP 000361. WO 2000/018824 discloses a process for the production of polybiphenyl sulfone polymers with a very small proportion of cyclic oligomers. EP 1272547 describes polybiphenyl sulfone polymers with a particularly low level of intrinsic color, obtained via equimolar condensation of the monomers 4,4′-dihydroxybiphenyl and 4,4′-dichlorodiphenyl sulfone in the presence of fine-particle potash.
WO 2005/095491 discloses that block copolymers having various polyarylene ether segments can be produced via coupling of separately produced blocks. Disadvantages of this method are not only the high cost for industrial implementation of this synthetic strategy but especially the lack of control of the stoichiometry, particularly when the intention is to couple blocks having molar masses above 5000 g/mol, since the determination of the respective block lengths is subject to error, and this often makes it difficult or impossible to obtain the necessary precision in establishment of the block lengths and of the molecular weights obtainable.
Moreover many of the polybiphenyl sulfone block copolymers obtainable from the prior art moreover have inadequate notched impact resistance, or else inadequate optical properties.